U.S. patent application number 11/828257 was filed with the patent office on 2008-01-31 for illumination device, and projection system including the same.
Invention is credited to Ji Hyouk Chung, Eun Seong SEO.
Application Number | 20080024740 11/828257 |
Document ID | / |
Family ID | 38728757 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080024740 |
Kind Code |
A1 |
SEO; Eun Seong ; et
al. |
January 31, 2008 |
ILLUMINATION DEVICE, AND PROJECTION SYSTEM INCLUDING THE SAME
Abstract
An illumination device and a projection system including the
same are disclosed. The illumination device can implement a
small-sized and high-efficiency projection system, and the
projection system includes the illumination device. The projection
system generates a light signal in which a luminous flux is
maximally distributed, and displays a desired image using the
generated light signal.
Inventors: |
SEO; Eun Seong; (Seoul,
KR) ; Chung; Ji Hyouk; (Seoul, KR) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
38728757 |
Appl. No.: |
11/828257 |
Filed: |
July 25, 2007 |
Current U.S.
Class: |
353/102 |
Current CPC
Class: |
G02B 19/0028 20130101;
G02B 27/0927 20130101; G03B 33/12 20130101; G02B 19/0061 20130101;
G02B 27/0983 20130101; G03B 33/06 20130101; G03B 21/2046 20130101;
G03B 21/2033 20130101 |
Class at
Publication: |
353/102 |
International
Class: |
G03B 21/20 20060101
G03B021/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 26, 2006 |
KR |
10-2006-0070200 |
Claims
1. An illumination device comprising: a light source for generating
a light signal; a switch for reconstructing a usage angle of the
light signal generated from the light source, and generating the
reconstructed light signal; and an illumination lens unit for
focusing the light signal generated from the switch.
2. The illumination device according to claim 1, wherein the switch
reconstructs the light signal at any one of angles
30.degree..about.60.degree..
3. The illumination device according to claim 1, wherein the switch
has a spherical or aspheric structure.
4. The illumination device according to claim 1, wherein the switch
includes: a first surface via which a low-refraction light signal
from among the light signal generated from the light source is
transmitted, and a high-refraction light signal is reflected; a
second surface having a curvature at which the light signal
transmitted from the first surface is reflected; and a third
surface via which the high-refraction light signal reflected from
the first surface is transmitted.
5. The illumination device according to claim 1, wherein the switch
includes: a first transmission surface via which a low-refraction
light signal from among the light signal generated from the light
source is transmitted; a first reflection surface via which the
light signal transmitted from the first transmission surface is
reflected; a second reflection surface via which the light signal
reflected from the first reflection surface is reflected; and a
second transmission surface via which the light signal reflected
from the second reflection surface is transmitted.
6. The illumination device according to claim 1, wherein the switch
includes: a first transmission surface via which a low-refraction
light signal from among the light signal generated from the light
source is transmitted; a first reflection surface via which the
light signal transmitted from the light source is reflected; a
second reflection surface via which the light signal transmitted
from the first transmission surface is reflected; a third
reflection surface via which the light signal reflected from the
second reflection surface is reflected; and a second transmission
surface via which the light signal reflected from the third
reflection surface is transmitted.
7. The illumination device according to claim 1, wherein the switch
reconstructs an output angle of the light signal via two or more
reflections of the light signal.
8. The illumination device according to claim 1, wherein the switch
further includes an optical fiber.
9. The illumination device according to claim 1, wherein the light
source is comprised of any one of a lamp and a light emitting diode
(LED).
10. The illumination device according to claim 1, wherein the
switch is located between the light source and the illumination
lens unit.
11. An illumination device comprising: a light source for
generating a light signal; a switch for reconstructing a reference
angle of an optic axis of the light signal generated from the light
source, and generating the reconstructed light signal; and an
illumination lens unit for receiving the light signal having the
reconstructed optic-axis reference angle from the switch, and
focusing the received light signal.
12. The illumination device according to claim 11, wherein the
switch reconstructs the optic-axis reference angle of the light
signal at any one of angles 30.degree..about.60.degree..
13. The illumination device according to claim 11, wherein the
switch reconstructs the optic-axis reference angle of the light
signal via two or more reflections of the light signal.
14. A projection display system comprising: an illumination unit
for generating a light signal, reconstructing a usage angle of the
light signal, and generating the reconstructed light signal; and a
projection unit for synthesizing the light signal generated from
the illumination unit, magnifying the synthesized light signal, and
imaging the magnified light signal.
15. The projection display system according to claim 14, wherein
the illumination unit reconstructs the usage angle of the light
signal at any one of angles 30.degree..about.60.degree..
16. The projection display system according to claim 14, wherein
the projection unit is configured in the form of a
transmission-type 3-chip structure or a 1-chip DLP (Digital
Lighting Processing) structure.
17. The projection display system according to claim 14, wherein
the illumination device includes: a plurality of light sources for
generating different-colored light signals.
18. A projection display system comprising: an illumination unit
for generating a light signal, reconstructing a reference angle of
an optic axis of the light signal, and generating the reconstructed
light signal; and a projection unit for synthesizing the light
signal generated from the illumination unit, magnifying the
synthesized light signal, and imaging the magnified light
signal.
19. The projection display system according to claim 18, wherein
the illumination unit reconstructs the optic-axis reference angle
of the light signal at any one of angles
30.degree..about.60.degree..
Description
[0001] This application claims the benefit of Korean Patent
Application No. 10-2006-0070200, filed on Jul. 26, 2006, which is
hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an illumination device, and
more particularly to an illumination device capable of implementing
a small-sized and high-efficiency projection system, and the
projection system including the illumination device.
[0004] 2. Discussion of the Related Art
[0005] Typically, an optical system for use in a projection engine
can be mainly classified into an illumination system and a
projection system.
[0006] The illumination system enables a light signal generated
from a lamp to pass through an integrator or FEL (Fly Eye Lens),
such that it uniformly applies the resultant light signal to a
small-sized imager.
[0007] The projection system enables the light signal generated
from the illumination system to be incident upon individual panels,
magnifies the imager, and forms an image on a screen.
[0008] In this case, the most important performance of the
above-mentioned projection engine is how the light signal generated
from the light source is effectively focused on the imager.
[0009] In the meantime, in order to increase efficiency of a light
signal of an illumination unit contained in the above-mentioned
illumination system, a specific output angle, at which a luminous
flux is maximally distributed, from among several output angles of
the light signal generated from the light source should be used as
a reference angle, such that the resultant light signal can be
effectively applied to illumination lenses.
[0010] However, the above-mentioned illumination lenses have a
rotational-symmetry structure and a fixed Etendue prescribed when
the illumination device is designed, such that the light source is
unable to use a desirable light signal in which a luminous flux is
maximally distributed.
[0011] In order to employ the above-mentioned desirable light
signal in which the luminous flux is maximally distributed, there
are needed a plurality of illumination lenses, each of which has a
large aperture, such that it is difficult to make a small-sized
illumination device, resulting in deterioration of light
efficiency.
SUMMARY OF THE INVENTION
[0012] Accordingly, the present invention is directed to an
illumination device and a projection system including the same that
substantially obviate one or more problems due to limitations and
disadvantages of the related art.
[0013] An object of the present invention is to provide an
illumination device for employing a light signal in which a
luminous flux is maximally distributed, and a projection system
including the illumination device.
[0014] Another object of the present invention is to provide a
small-sized illumination device with high efficiency, and a
projection system including the same.
[0015] Additional advantages, objects, and features of the
invention will be set forth in part in the description which
follows and in part will become apparent to those having ordinary
skill in the art upon examination of the following or may be
learned from practice of the invention. The objectives and other
advantages of the invention may be realized and attained by the
structure particularly pointed out in the written description and
claims hereof as well as the appended drawings.
[0016] To achieve these objects and other advantages and in
accordance with the purpose of the invention, as embodied and
broadly described herein, an illumination device comprises: a light
source for generating a light signal; a switch for reconstructing a
usage angle of the light signal generated from the light source,
and generating the reconstructed light signal; and an illumination
lens unit for focusing the light signal generated from the
switch.
[0017] In another aspect of the present invention, there is
provided an illumination device comprising: a light source for
generating a light signal; a switch for reconstructing a reference
angle of an optic axis of the light signal generated from the light
source, and generating the reconstructed light signal; and an
illumination lens unit for receiving the light signal having the
reconstructed optic-axis reference angle from the switch, and
focusing the received light signal.
[0018] In yet another aspect of the present invention, there is
provided a projection display system comprising: an illumination
unit for generating a light signal, reconstructing a usage angle of
the light signal, and generating the reconstructed light signal;
and a projection unit for synthesizing the light signal generated
from the illumination unit, magnifying the synthesized light
signal, and imaging the magnified light signal.
[0019] In yet another aspect of the present invention, there is
provided a projection display system comprising: an illumination
unit for generating a light signal, reconstructing a reference
angle of an optic axis of the light signal, and generating the
reconstructed light signal; and a projection unit for synthesizing
the light signal generated from the illumination unit, magnifying
the synthesized light signal, and imaging the magnified light
signal.
[0020] It is to be understood that both the foregoing general
description and the following detailed description of the present
invention are exemplary and explanatory and are intended to provide
further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this application, illustrate embodiment(s) of
the invention and together with the description serve to explain
the principle of the invention. In the drawings:
[0022] FIG. 1 is a conceptual diagram illustrating an illumination
device according to a first preferred embodiment of the present
invention;
[0023] FIG. 2 is a conceptual diagram illustrating an illumination
device according to a second preferred embodiment of the present
invention;
[0024] FIG. 3 is a conceptual diagram illustrating an illumination
device according to a third preferred embodiment of the present
invention;
[0025] FIG. 4 shows a pupil map and a luminous-flux distribution
according to the present invention;
[0026] FIG. 5 is a usage angle of a light signal for use in a
general illumination device;
[0027] FIG. 6 shows a luminous-intensity distribution of a
Lambertian source according to the present invention;
[0028] FIG. 7 shows a definition of a solid angle d.theta.cell of a
Lambertian source and a distribution of a luminous flux incident
upon the solid angle d.theta.cell according to the present
invention;
[0029] FIG. 8 shows a pupil map for use in a general illumination
device;
[0030] FIG. 9 shows a luminous flux distributed at an output angle
.theta. selected on the pupil map of FIG. 6 according to the
present invention;
[0031] FIG. 10 is a block diagram illustrating a projection display
system including an illumination device according to a fourth
preferred embodiment of the present invention;
[0032] FIG. 11 is a block diagram illustrating a transmission-type
3-chip projection display system including an illumination device
according to a fifth preferred embodiment of the present
invention;
[0033] FIG. 12 is a block diagram illustrating a 1-chip DLP
(Digital Lighting Processing) projection display system including
an illumination device according to a sixth preferred embodiment of
the present invention; and
[0034] FIG. 13 is a block diagram illustrating a projection display
system including an illumination device according to a seventh
preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers will be used throughout the drawings to
refer to the same or like parts.
[0036] FIG. 1 is a conceptual diagram illustrating an illumination
device according to a first preferred embodiment of the present
invention.
[0037] Referring to FIG. 1, the illumination device according to a
first preferred embodiment of the present invention includes a
light source 10 for generating a light signal; a switch 11 for
reconstructing a usage angle of the light signal generated from the
light source 10, and generating the reconstructed light signal; and
an illumination lens 12 for focusing the light signal generated
from the switch 11, and generating the focused light signal.
[0038] The light source 10 may include a plurality of light sources
such as lamps or LEDs.
[0039] The switch 11 is located between the light source 10 and the
illumination lens 12, and reconstructs the usage angle of the light
signal applied to the illumination lens 12 at any one of angles
30.degree..about.60.degree..
[0040] If a light source 10 based on the Lambertian divergence
scheme is indicative of the LED, the switch 11 reconstructs the
usage angle of the light signal at an angle of .+-.45.degree., such
that the reconstructed light signal is incident upon the
illumination lens 12.
[0041] The switch 11 has an outer surface configured in the form of
a spherical- or aspheric structure, and an inner surface thereof is
opened at a predetermined angle on the basis of an optic axis. As a
result, the switch 11 reconstructs the usage angle of the light
signal via at least two reflections, such that the luminous flux is
maximally distributed at the reconstructed usage angle.
[0042] The switch 11 is made of a transparent material capable of
reflecting the light signal at a high refraction rate. For example,
the switch 11 is made of glass or PMMA (Poly Methylmethacrylate).
In the case of fabricating the switch 11, the above-mentioned
material is melted, and the switch 11 having a thickness of
10.about.40 mm is manufactured by a frame or mold.
[0043] The switch 11 includes: a first surface 11a via which a
low-refraction light signal from among the light signal generated
from the light source 10 is transmitted, and a high-refraction
light signal is reflected; a second surface 11b having a curvature
at which the light signal transmitted from the first surface 11a is
reflected; and a third surface 11c via which the high-refraction
light signal reflected from the first surface 11a is transmitted
such that the resultant high-refraction light signal is applied to
an illumination lens 12.
[0044] The first surface 11a is indicative of a first transmission
surface 11a arranged at a specific surface on which the light
signal generated from the light source 10 is incident.
[0045] The second surface 11b is coated with a reflective layer, is
arranged on a specific surface facing the first transmission
surface 11a, and reflects the light signal transmitted from the
first transmission surface 11a.
[0046] The first surface 11a re-reflects the high-refraction light
signal reflected from the second surface 11b.
[0047] The third surface 11c serves as a transmission surface,
enables the light signal reflected from the first surface 11a to be
transmitted, and outputs the resultant light signal to the
illumination lens 12.
[0048] In operations, it is noted that the usage angle of the light
signal is defined as .alpha.=.+-.45.degree., and an angle allowed
by an Etendue is defined as .beta.=.+-.15.degree..
[0049] The usage angle of the light signal from the light source 10
to the switch 11 is in the range from 0.degree. to 90.degree. on
the basis of an optic axis. The usage angle of the light signal
incident upon the first transmission surface 11a is in the range
from 0.degree. to 45.degree. on the basis of the optic axis.
[0050] As can be seen from FIG. 1, the light signal is reflected
from the switch 11 two times, such that the resultant light signal
having a user-desired output angle is focused on the basis of the
optic axis of the illumination lens 12. In this way, only the light
signal in which a luminous flux indicating the user-desired usage
angle is maximally distributed is selectively used, and the light
signal is illuminated on the projection device (not shown) via the
illumination lens unit 12, such that the image is projected.
[0051] The switch 11 may reconstruct the usage angle of the light
signal via at least two reflections of the light signal. And, the
usage angle may be set to a specific angle at which the shape of
the switch 11 is formed, and the output angle of the light signal
may be reconstructed as the specific angle.
[0052] For example, the angle at which the first transmission
surface 11a and the second reflection surface 11c are formed, and
the angle of the second reflection surface 11c are adjusted, such
that the usage angle of the output light signal can be
adjusted.
[0053] According to the above-mentioned first preferred embodiment
of the present invention, an angle between two first transmission
surfaces 11a is set to 45.degree..
[0054] FIG. 2 is a conceptual diagram illustrating an illumination
device according to a second preferred embodiment of the present
invention.
[0055] Referring to FIG. 2, similar to the illumination device of
FIG. 1, the illumination device according to the second preferred
embodiment of the present invention includes a light source 20, a
switch 21, and an illumination lens 22. Therefore, the same
components as those of FIG. 1 will herein be omitted for the
convenience of description.
[0056] The switch 21 includes: a first transmission surface 21a via
which a low-refraction light signal from among the light signal
generated from the light source 20 is transmitted; a first
reflection surface 21b having a curvature at which the light signal
transmitted from the first transmission surface 21a is reflected; a
second reflection surface 21c via which the light signal reflected
from the first reflection surface 21b is re-reflected; and a second
transmission surface 21d via which the light signal reflected from
the second reflection surface 21c is transmitted such that the
resultant light signal is applied to the illumination lens 22.
[0057] In more detail, the switch 21 includes: a first transmission
surface 21a arranged on an incident surface of the light signal
generated from the light source 20; a first reflection surface 21b
arranged to face the first transmission surface 21a, such that it
reflects the light signal transmitted from the first transmission
surface 21a; a second reflection surface 21c arranged to face the
first reflection surface 21a, such that it reflects the light
signal reflected from the first reflection surface 21b; and a
second transmission surface 21d arranged to face the second
reflection surface 21c, for enabling the light signal reflected
from the first reflection surface 21a to be transmitted, and
applying the resultant light signal to the illumination lens
22.
[0058] In operations, it is noted that the usage angle of the light
signal is defined as .alpha.=.+-.45.degree., and an angle allowed
by an Etendue is defined as .beta.=.+-.15.degree..
[0059] The usage angle of the light signal from the light source 20
to the switch 21 is in the range from 0.degree. to 90.degree. on
the basis of an optic axis. The usage angle of the light signal
incident upon the first transmission surface 21a is in the range
from 0.degree. to 45.degree. on the basis of the optic axis.
[0060] As can be seen from FIG. 2, the light signal is reflected
from the switch 21 two times, such that the resultant light signal
having a user-desired output angle is focused on the basis of the
optic axis of the illumination lens 22. In this way, only the light
signal in which a luminous flux indicating the user-desired usage
angle is maximally distributed is selectively used, and the light
signal is illuminated on the projection device (not shown) via the
illumination lens unit 22, such that the image is projected.
[0061] The switch 21 may reconstruct the usage angle of the light
signal via at least two reflections of the light signal. Also, the
output angle may be set to a specific angle at which the shape of
the switch 21 is formed, such that the output angle of the light
signal may be reconstructed as the specific angle.
[0062] For example, the angle at which the first transmission
surface 21a and the second reflection surface 21c are formed, and
the angle of the second reflection surface 21c are adjusted, such
that the usage angle of the output light signal can be
adjusted.
[0063] According to the above-mentioned second preferred embodiment
of the present invention, the angle of the second reflection
surface 21c is set to 45.degree., and an angle at which the first
transmission surface 21a and the second reflection surface 21c are
formed is set to 5.degree..
[0064] FIG. 3 is a conceptual diagram illustrating an illumination
device according to a third preferred embodiment of the present
invention.
[0065] Referring to FIG. 3, similar to the illumination device of
FIG. 1, the illumination device according to the third preferred
embodiment of the present invention includes a light source 30, a
switch 31, and an illumination lens 32, such that the same
components as those of FIG. 1 will herein be omitted for the
convenience of description.
[0066] The switch 31 includes: a first transmission surface 31a via
which a low-refraction light signal from among the light signal
generated from the light source 30 is transmitted; a first
transmission surface 31b via which the light signal transmitted
from the light source 30 is reflected; a second reflection surface
31c having a curvature at which the light signal transmitted from
the first transmission surface 31a is reflected; a third reflection
surface 31d via which the high-refraction light signal reflected
from the second reflection surface 31c is re-reflected; and a
second transmission surface 31e via which the light signal
reflected from the third reflection surface 21d is transmitted such
that the resultant light signal is applied to the illumination lens
32.
[0067] In more detail, the switch 31 includes: a first transmission
surface 31a arranged on a specific surface on which the light
signal transmitted from the light source 30 is incident in a
straight line; a second reflection surface 31c arranged to face the
first transmission surface 31a such that it reflects the light
signal transmitted from the first transmission surface 31a; a first
reflection surface 31b arranged on any one of surfaces facing the
second reflection surface 31c, such that it reflects the light
signal generated from the light source 30; a third reflection
surface 31d arranged on any one of surfaces facing the second
reflection surface 31c, such that it reflects the light signal
reflected from the second reflection surface 31c; and a second
transmission surface 31e arranged on any one of surfaces facing the
third reflection surface 31d, for enabling the light signal
reflected from the third reflection surface 31d to be transmitted,
and applying the resultant light signal to the illumination lens
32.
[0068] In operations, it is noted that an optic-axis reference
angle of the light signal is defined as .alpha.=.+-.45.degree., and
an optic-axis allowable angle allowed by an Etendue is defined as
.beta.=.+-.15.degree..
[0069] The optic-axis reference angle of the light signal from the
light source 30 to the switch 31 is in the range from 0.degree. to
90.degree. on the basis of an optic axis. The optic-axis reference
angle of the light signal incident upon the first transmission
surface 31a is in the range from 0.degree. to 45.degree..
[0070] As can be seen from FIG. 3, the light signal is reflected
from the switch 31 three times, such that the resultant light
signal having a user-desired optic-axis reference angle of
.+-.45.degree. is focused on the illumination lens 22.
[0071] In this way, only the light signal in which a luminous flux
is maximally distributed is selectively used, and the light signal
is illuminated on the projection device (not shown) via the
illumination lens unit 32, such that the image is projected.
[0072] The switch 31 may reconstruct the optic-axis reference angle
of the light signal via at least three reflections of the light
signal.
[0073] The optic-axis reference angle is indicative of a specific
angle at which the shape of the switch 31 is formed, such that the
optic-axis reference angle of the light signal may be reconstructed
as the specific angle.
[0074] For example, a first angle between the first transmission
surface 31a and the first reflection surface 31b, a second angle
between the first transmission surface 31a and the second
reflection surface 31c, a third angle between the second reflection
surface 31c and the second transmission surface 31e, and a fourth
angle between the first reflection surface 31b and the third
reflection surface 31d are adjusted such that the optic-axis
reference angle of the light signal can also be adjusted.
[0075] According to the above-mentioned third preferred embodiment
of the present invention, the angle between the first transmission
surface 31a and the first reflection surface 31b is set to
7.degree., the angle between the first transmission surface 31a and
the second reflection surface 31c is set to 30.degree., the angle
between the second transmission surface 31c and the second
transmission surface 31e is set to 25.degree., and the angle
between the first reflection surface 31b and the third reflection
surface 31d is set to 3.degree..
[0076] Each of the above-mentioned switches 11, 21, and 31 may
include an optical fiber (not shown).
[0077] The output angle of the light signal generated from the
light source 10, 20, and 30 is in the range from 0.degree. to
90.degree., and the usage angle of the incident light signal is in
the range from 0 to 45.degree.. Under this condition, the
illumination device enables the light signal to pass through the
optical fiber, such that the usage angle or optic-axis reference
angle of the light signal ranging from the optical fiber to the
illumination lens may be reconstructed at an angle of
.+-.45.degree..
[0078] FIG. 4 shows a pupil map and a luminous-flux distribution
according to the present invention.
[0079] FIG. 4A shows a pupil map according to first to second
preferred embodiments of the present invention. FIG. 4B shows a
pupil map according to a third preferred embodiment of the present
invention. FIG. 4C is a graph illustrating a luminous flux
according to first to third preferred embodiments of the present
invention.
[0080] If an amount of Etendue of the projection system is
determined, a user-desired angle at a central point of the Etendue
range must be set to a central angle.
[0081] For example, provided that the central angle is set to
.alpha..degree., an Etendue-allowed angle is set to .beta..degree.,
and the pupil maps shown in the above-mentioned first to third
preferred embodiments of the present invention are applied to the
above-mentioned angles, the illumination lens receives the light
signal in which the luminous flux is maximally distributed, such
that the projection system including the above-mentioned
illumination lens may have the highest efficiency.
[0082] As can be seen from FIG. 4A, .alpha..degree.-.beta..degree.
may be set to the central point of the pupil map, and
.alpha..degree.+.beta..degree. may be set to the maximum angle
allowed by Etendue.
[0083] As can be seen from FIG. 4B, .alpha..degree.+.beta..degree.
may be set to the central point of the pupil map, and
.alpha..degree.-.beta..degree. may be set to the maximum angle
allowed by Etendue. Other unused angles are arranged outside of the
Etendue-allowed area.
[0084] If the luminous flux is used as described above, the
distributed graph is shown in FIG. 4C, such that the illumination
device according to the present invention can acquire the maximum
light efficiency. As a result, the projection including the
illumination device can also acquire the maximum light
efficiency.
[0085] A conventional art associated with the present invention
will hereinafter be described with reference to FIGS.
5.about.9.
[0086] FIG. 5 is a usage angle of a light signal for use in a
general illumination device.
[0087] Referring to FIG. 5, the illumination device selects only a
predetermined angle from among 0.degree. to other degrees on the
basis of the optic axis of the illumination lens, and uses the
selected angle.
[0088] In this case, if the light-amount distribution of the
illumination device is set to 0.degree., the conventional
illumination device can acquire the maximum efficiency. However, a
light amount of a general light source, i.e., the maximum
distribution of the luminous flux, has a maximum light-amount value
at an angle of .+-.45.degree., instead of the above angle of
0.degree..
[0089] For example, although a general illumination device for
using the lamp as a light source determines its own maximum
light-amount value according to reflection-surface shapes, it
should be noted that the maximum light-amount value is actually
distributed at the angle of 30.degree. on the basis of the optic
axis.
[0090] Most general illumination devices follow the Lambertian
divergence scheme. In this way, if the general illumination devices
follow the Lambertian divergence scheme, the maximum light-amount
value is distributed at the angle of 45.degree. on the basis of the
optic axis.
[0091] The luminous-intensity distribution of the Lambertian source
can be represented by the following Equation 1, and the graph
illustrating the luminous-intensity distribution is shown in FIG.
6:
I=I.sub.0 cos .theta. [Equation 1]
[0092] The light signal incident upon the Lambertian source's solid
angle d.theta.cell can be represented by the following Equation
2:
L .theta. .varies. I 0 cos .theta. sin .theta. [ Equation 2 ]
##EQU00001##
[0093] The resultant value of Equation 2 can be represented by the
graph of FIG. 7A.
[0094] FIG. 7B shows a graph illustrating the luminous flux
incident upon the solid angle d.theta.cell. As can be seen from
FIG. 7B, it can be recognized that the largest amount of luminous
flux is maximally distributed in the vicinity of the angle of
45.degree..
[0095] Therefore, it can be recognized that the above-mentioned
illumination device capable of using a predetermined angle .theta.'
on the basis of the angle of 45.degree. has a luminous flux higher
than that of the conventional illumination device capable of using
a predetermined angle .theta.' on the basis of the angle of
0.degree..
[0096] FIG. 8A shows a pupil map for use in a general illumination
device. In more detail, FIG. 8A shows a pupil map in which the
angle of the light signal generated from the light source is
arranged at a specific position. The iris diaphragm (i.e., stop) of
the illumination device corresponds to the above-mentioned specific
position.
[0097] As shown in FIG. 8A, 0.degree. is located at the center part
of the pupil map, and 90.degree. is located at the outermost part
of the pupil map. A plurality of concentric circles may be drawn at
individual angles.
[0098] In this case, the circle may be cut by a predetermined area
according to Etendue of the illumination device, and is then used
as necessary.
[0099] The Etendue of the illumination device is fixed, such that
the illumination device can employ the light signal in the range
from 0.degree. to a predetermined angle based on the Etendue in the
light signal generated from the light source.
[0100] FIG. 8B shows a pupil map of a general illumination device.
In FIG. 5B, the illumination lens focuses the light signal in the
range from 0.degree. to a predetermined angle, and is unable to
focus the light signal at the remaining angles other than the
above-mentioned range from 0.degree. to the predetermined
angle.
[0101] Referring to FIG. 5B, according to the general illumination
device, the light signal having an output angle 90.degree. on the
basis of the light source is next to the other light signal having
an output angle .theta..degree. on the basis of the light source,
such that the light signal having the output angle 90.degree.
occupies a corresponding position in the pupil map. The light
signal having an angle larger than the angle .theta..degree.
occupies the last position in the pupil map.
[0102] Therefore, the resultant light signal to be used has the
angle of FIG. 8B. According to the method of FIG. 8B, the
illumination device uses other angles other than the maximum
angle.
[0103] Provided that the Lambertian source is applied to the
example of FIG. 5B, the maximum distribution graph of the luminous
flux has a symmetrical structure on the basis of the angle
45.degree., such that maximum light efficiency can be acquired on
the condition that the luminous flux distributed at the angle of
.+-.45.degree. is used.
[0104] FIG. 9A is a graph illustrating a luminous flux distributed
at an output angle of .theta. arbitrarily selected on the pupil
map. The hatched area of FIG. 9A indicates an amount of luminous
flux.
[0105] As described above, the general illumination device does not
use the light signal in which the luminous flux is maximally
distributed.
[0106] Therefore, in order to acquire a maximum light amount from
the illumination device, not only the pupil map in which the
luminous flux incident upon the illumination lens is maximally
distributed, but also the graph must be equal to those of FIG.
4.
[0107] A projection display system using the above-mentioned
illumination device will hereinafter be described with reference to
the annexed drawings.
[0108] FIG. 10 is a block diagram illustrating a projection display
system including an illumination device according to a fourth
preferred embodiment of the present invention.
[0109] Referring to FIG. 10, the projection display system includes
an illumination system 60 and a projection system 70.
[0110] The projection system 70 includes a projection lens 72, a
plurality of color-selection polarization plates 74.about.76, a
dichroic filter 78, and a plurality of LCD panels 80, 82, and
84.
[0111] The illumination system includes the above-mentioned
illumination device according to the present invention, serves as a
light source of the projection display system, and applies the
light signal to the projection system 709.
[0112] FIG. 11 is a block diagram illustrating a transmission-type
3-chip projection display system including an illumination device
according to a fifth preferred embodiment of the present
invention.
[0113] Referring to FIG. 11, the transmission-type 3-chip
projection display system includes a plurality of illumination
devices 110, 112, and 114, an illumination lens system 116, a
plurality of LCD panels 122, 124, and 126, a plurality of
reflective mirrors 118 and 120, a synthesizer 128, and a projection
lens system 130.
[0114] In this case, the constituent components 116.about.130 other
than the illumination devices 110, 112, and 114 have the same
functions as those of the projection system 70 shown in FIG. 8.
[0115] Referring to FIG. 11, the illumination devices 110, 112, and
114 uniformly generate a red (R) light signal, a green (G) light
signal, and a blue (B) light signal, respectively. The R, G, and B
light signals pass through the illumination lens system 116 and the
reflective mirrors 118.about.120, and are then applied to the
synthesizer 128 via the LCD panels 122, 124, and 126.
[0116] In this case, the synthesizer 128 indicating an X-shape
prism synthesizes the light signals received via the LCD panels
122, 124, and 126. The projection lens system 130 magnifies the
resultant light signals synthesized by the synthesizer 128, and
forms an image on the screen.
[0117] FIG. 12 is a block diagram illustrating a 1-chip DLP
(Digital Lighting Processing) projection display system including
an illumination device according to a sixth preferred embodiment of
the present invention.
[0118] Referring to FIG. 12, the 1-chip DLP (Digital Lighting
Processing) projection display system includes a plurality of
illumination devices 140, 142, and 144, a plurality of illumination
lens systems 146 and 150, a synthesizer 148, a TIR (Total Internal
Reflection) prism 152, an LCD panel 154, and a projection lens
system 156.
[0119] In this case, the constituent components other than the
illumination devices 140, 142, and 144 have the same functions as
those of the projection system 70 shown in FIG. 8.
[0120] Referring to FIG. 12, the illumination devices 140, 142, and
144 generate a red (R) light signal, a green (G) light signal, and
a blue (B) light signal, respectively. The R, G, and B light
signals are illuminated on the illumination lens system 146.
[0121] In this case, the synthesizer 148 receives the light signals
from the illumination devices 140, 142, and 144 via the
illumination lens system 146, and synthesizes the received light
signals. The synthesized result is applied to the projection lens
system 156 via the TIR prism 152 and the LCD panel 154, such that
the projection lens system 156 magnifies the resultant light
signals, and forms an image on the screen.
[0122] FIG. 13 is a block diagram illustrating a projection display
system including an illumination device according to a seventh
preferred embodiment of the present invention.
[0123] Referring to FIG. 13, the projection display system
according to the seventh preferred embodiment of the present
invention includes an illumination device 160, an illumination lens
system 162, a TIR system 164, an LCD panel 166, and a projection
lens system 168.
[0124] The illumination device 160 shown in FIG. 13 includes a
plurality of light sources capable of generating different-colored
light signals.
[0125] For example, the illumination device 160 may include LEDs
for generating RGB light signals. In this case, there is no need to
use the synthesizer 128 or 148 of FIG. 10 or 11.
[0126] The illumination lens system 162, the TIR prism 164, the LCD
panel 166, and the projection lens system 168 shown in FIG. 13 have
the same functions as the illumination lens system 150, the TIR
prism 152, the LCD panel 154, and the projection lens system 156
shown in FIG. 10, such that a detailed description thereof will
herein be omitted for the convenience of description.
[0127] The projection display system shown in FIG. 13 controls a
plurality of LED light sources, forms images of individual colors,
synthesizes the formed images into a single image, and forms the
synthesized images on the screen via the projection lens system
168.
[0128] As apparent from the above description, the present
invention provides an illumination device capable of generating a
light signal in which a luminous flux is maximally distributed,
such that it provides a small-sized projection system having
high-quality video data.
[0129] The illumination device employs light signal in which a
luminous flux is maximally distributed, and the projection system
includes the illumination device therein.
[0130] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the inventions. Thus,
it is intended that the present invention covers the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *